Protection by BCG against tuberculosis : a systematic review of randomised controlled trials

Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK Respiratory Diseases Department, Health Protection Agency, 61 Colindale, London NW9 5EQ, UK School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK Research Department of Infection and Population Health, University College Mortimer MarketCentre, London WC1E 6JB London, UK Centre for Respiratory Medicine, Royal Free Campus, University College, Rowland Hill Street, London, NW3 2PF , UK MRC Human Nutrition Research, University of Cambridge, Elsie Widdowson Laboratory 120 Fulbourn Road, Cambridge, CB1 9NL UK